Introducing PDMS layer on PSF membrane to enhance CO₂/CH₄separation

Biogas is a renewable energy that can overcome the dependency on fossil fuel usage. However, the purification of methane gas from other impurities is necessary. PSF membrane is proposed to separate CO2 and CH4 gas for biogas upgrading. In order to obtain better CO2/CH4 selectivity, PDMS coating on the PSF membrane surface was conducted. All membranes were characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD analysis exhibits a typical peak of polysulfone (PSF) and polydimethylsiloxane (PDMS) in the membrane at 2? = 17.67 and 12.16°, respectively. After PDMS coating, the PSF membrane surface morphology became smoother. Coating PDMS onto the PSF membrane boosts CO2/CH4 selectivity from 3.35 to 4.80 (+47.16%). Moreover, PDMS/PSF membrane generated 83.14% higher CH4 concentration than the neat membrane (7.96% greater).